The present invention relates to an improvement in a vacuum deposition apparatus including a vacuum chamber, a substrate to form a thin film thereon provided in the vacuum chamber, and a reactor unit spaced a given distance from the substrate for forming a thin film on the substrate.
Such a vacuum deposition apparatus is used to form a thin film on a substrate by plasma chemical vapor deposition (plasma CVD), for example.
FIG. 11 shows a vacuum deposition apparatus in the related art. The vacuum deposition apparatus shown in FIG. 11 includes a vacuum chamber 1000. Provided in the vacuum chamber 1000 are a scan roll 1001, a supply roll 1002, a take-up roll 1003, a base 1004, an electrode 1005, a gas inlet pipe 1006, and a reactor 1007.
The electrode 1005 is provided in the reactor 1007, and a voltage is applied from a DC power supply 1009 to the electrode 1005, thereby forming a thin film on an elongated film-like substrate 1010 by plasma CVD. The substrate 1010 is supplied from the supply roll 1002, next wrapped around the scan roll 1001, and finally taken up by the take-up roll 1003. At this time, reactant gases are introduced from a reactant gas source (not shown) through the gas inlet pipe 1006 to the reactor 1007.
The reactor 1007 is supported to a gap adjusting stage 1011 fixed through the base 1004 to a floor surface or inner wall of the vacuum chamber 1000. The gap adjusting stage 1011 can accurately adjust the position of the reactor 1007 relative to the scan roll 1001 to maintain uniform a gap D between the rector 1007 and the scan roll 1001.
However, in carrying out maintenance work of the reactor 1007 such as cleaning of the inside of the reactor 1007, the rector 1007 must be demounted from the base 1004 and taken out of the vacuum chamber 1000. Such a work to remove a reactor for maintenance requires much time, so that it is undesirable to fix the reactor 1007 in the vacuum chamber 1000.
To cope with this problem, there has been proposed another vacuum deposition apparatus as shown in FIGS. 12 and 13.
This vacuum deposition apparatus employs a moving carriage 1020. A door 1031 for closing an opening 1033 of a vacuum chamber 1030 is mounted on the moving carriage 1020. A gas inlet pipe 1006 and a reactor 1007 are provided so as to be moved by the moving carriage 1020. The reactor 1007 is supported to supporting arms 1032 extending from the door 1031 into the vacuum chamber 1030. A gap adjusting stage 1011 is mounted on the supporting arms 1032 so as to adjust the position of the reactor 1007 relative to the scan roll 1001. With this configuration, the reactor 1007 set in the vacuum chamber 1030 can be easily taken out by moving the moving carriage 1020 in the direction of an arrow X2, thereby allowing easy maintenance of the reactor 1007 such as cleaning.
When the moving carriage 1020 is moved in the direction of an arrow X1 to close the opening 1033 of the vacuum chamber 1030 by means of the door 1031 and to evacuate the vacuum chamber 1030, an atmospheric pressure is applied to the door 1031, removing air from the vacuum chamber 1030 to cause a large warpage of the door 1031 inward of the vacuum chamber 1030 as shown in FIG. 13.
As a result, the position of the reactor 1007 set in the vacuum chamber 1030 is changed and the gap D formed between the substrate 1010 on the scan roll 1001 and the reactor 1007 is therefore changed, so that adjustment in position between the reactor 1007 and the substrate 1010 wrapped around the scan roll 1001 becomes very difficult. Accordingly, there occurs a problem that a thin film cannot be accurately formed on the substrate 1010 by plasma CVD.